The highest tides in the world are in the Bay of Fundy, Canada, where Burntcoat Head in the Minas Basin has a mean tidal range of 11.7 m (38.4 ft). Second is Ungava Bay in northern Quebec, at 9.75 m (32.0 ft) near the mouth of the Leaf River, and third is the Bristol Channel between England and Wales, at 9.6 m (31.5 ft) at Avonmouth. Those figures come from the US National Oceanic and Atmospheric Administration (NOAA), whose list of the 50 places with the largest tidal ranges was consulted in October 2026. They are averages, the gap between mean high water and mean low water. On the biggest spring tides the range is much larger: about 16 m in Fundy, with 17.0 m predicted as the extreme. The open ocean, by comparison, rises and falls only about 1 m.
How NOAA’s list of 50 tidal stations becomes a top 10
NOAA ranks tide stations, not bays, and stations cluster. Its first six places all belong to the Bay of Fundy (Burntcoat Head, Horton Bluff, Amherst Point, Parrsboro, Hopewell Cape and Joggins), and with Grindstone Island and Spencer Island the bay holds eight of the top ten. The countdown below gives each bay, strait or estuary one place, ranked by its best station. A few stations are left out because they sit in a gulf already counted. Jersey’s Les Minquiers (7.65 m), for example, belongs to the same gulf as Granville in Normandy.
All ten places are “hypertidal”, the term coastal scientists use when the range passes 6 m. Anything over 4 m counts as macro-tidal, and the Mediterranean, Baltic and Caribbean barely move at all. The pattern explained in what causes tides sets the twice-daily rhythm, but local shape decides the height. A wide continental shelf, a basin that narrows like a funnel, and a natural sloshing period close to the 12.4-hour lunar tide can multiply an ocean swell of a metre several times over.
| Rank | Place (best NOAA station) | Country | Mean range |
|---|---|---|---|
| 1 | Bay of Fundy (Burntcoat Head) | Canada | 11.70 m (38.4 ft) |
| 2 | Ungava Bay (Leaf Lake) | Canada | 9.75 m (32.0 ft) |
| 3 | Bristol Channel (Avonmouth) | United Kingdom | 9.60 m (31.5 ft) |
| 4 | Cook Inlet (Sunrise, Turnagain Arm) | United States | 9.24 m (30.3 ft) |
| 5 | Río Gallegos estuary (Reducción Beacon) | Argentina | 8.84 m (29.0 ft) |
| 6 | Gulf of Saint-Malo (Granville) | France | 8.60 m (28.2 ft) |
| 7 | Strait of Magellan (Banco Dirección) | Chile | 8.53 m (28.0 ft) |
| 8 | Ría Coig | Argentina | 8.11 m (26.6 ft) |
| 9 | Santa Cruz estuary (Punta Quilla) | Argentina | 7.92 m (26.0 ft) |
| 10 | Cape Astronomicheski, Kamchatka | Russia | 7.35 m (24.1 ft) |
Numbers 10 to 8: Kamchatka and two Patagonian rivers
10. Cape Astronomicheski, Kamchatka, Russia: 7.35 m. The only Asian entry in NOAA’s list. The Sea of Okhotsk is a large, partly enclosed basin, and its long north-eastern inlets carry big tides. Penzhina Bay, a 300 km inlet between the Kamchatka and Taygonos peninsulas, has the highest tides of any bay on the Pacific, about 9 m on average and up to 12.9 m. The size of those tides has prompted several proposals for a tidal power station, none of which has been built.
9. Santa Cruz estuary (Punta Quilla), Argentina: 7.92 m. Argentina gets three places in this top ten because the Patagonian shelf off Santa Cruz province is broad and shallow, so the Atlantic tide slows and piles up as it crosses it. NOAA lists Punta Quilla, at the mouth of the Santa Cruz River, at 26.0 ft.
8. Ría Coig, Argentina: 8.11 m. A little further south, the Coig (Coyle) estuary records 26.6 ft. The coast here is a run of drowned river mouths, and each one funnels the incoming tide into a narrower channel.
Numbers 7 to 5: Magellan, Normandy and Río Gallegos
7. Strait of Magellan (Banco Dirección), Chile: 8.53 m. The strait shows how much basin shape matters. On its Atlantic side the tide is semidiurnal with a mean range of 7.1 m and a spring range of 9.0 m. On its Pacific side, at the other end of the same channel, the mean range is just 1.1 m. Bahía Posesión, near the Atlantic entrance, records 8.38 m on NOAA’s list.
6. Gulf of Saint-Malo (Granville), France: 8.60 m. Europe’s highest tides fill the gulf between Brittany, Normandy and the Channel Islands. Granville closes the north of the Bay of Mont-Saint-Michel, and its harbour sees spring ranges of up to 14 m. Cancale (8.47 m) and Saint-Malo (7.99 m) are on the same list. Around Mont-Saint-Michel the gap between the highest and lowest water is roughly 14 m. On 21 March 2015 a once-in-18-years tide put the new access bridge completely under water. The same tide powers the Rance Tidal Power Station near Saint-Malo, opened in 1966. Its 240 MW plant was the largest of its kind for 45 years, until South Korea’s 254 MW Sihwa Lake station opened in 2011.
5. Río Gallegos estuary, Argentina: 8.84 m. The Reducción Beacon in the Gallegos estuary is the highest station in the Southern Hemisphere on NOAA’s list, at 29.0 ft. Río Gallegos, the capital of Santa Cruz province (population 115,524 in the 2022 census), sits on the estuary’s shore.
Number 4: Turnagain Arm and Cook Inlet, Alaska
4. Cook Inlet (Sunrise, Turnagain Arm), United States: 9.24 m. NOAA explains the case directly: the coast of southern Alaska and British Columbia acts as a funnel with Cook Inlet at its narrow end. Ocean water spread over a wide area is pushed into a smaller and smaller channel, so it rises. Stations on the Bering Sea, at the same latitude but outside the funnel, see only 1.5–2.1 m.
Turnagain Arm, the inlet’s southern branch, has the largest tides in the United States, up to 12 m (40 ft) on big springs. The flood often arrives as a bore up to 1.8 m (6 ft) high, which kayakers and surfers ride, and the currents in the inlet reach about 6 knots. On his 1778 voyage Captain James Cook found the arm impossible to navigate against the currents and mudflats, then ran HMS Resolution onto a sandbar on the way out and had to wait for the tide to free her. Frustrated, he named it “Turn Again”.
Numbers 3 and 2: the Severn bore and the Leaf River
3. Bristol Channel (Avonmouth), United Kingdom: 9.60 m. Britain fills seven of NOAA’s 50 places with Bristol Channel stations, among them Avonmouth, Newport (9.24 m), Burnham on the Parrett (9.11 m), Weston-super-Mare (8.99 m) and Cardiff (8.56 m). The tidal wave approaches Europe about 1,100 km wide and narrows to about 320 km over the continental shelf. Approaching the Severn it is squeezed from about 160 km to under 8 km, and the maximum range reaches 15 m.
Above Sharpness, the incoming tide forms the Severn bore, a series of waves up to 2 m high that runs upriver towards Gloucester. It appears on about 130 days a year, two bores a day, and is biggest just after new and full moons near the equinoxes. Jack Churchill, a Second World War veteran, first surfed it in 1955. In March 2006 Steve King rode it for 12 km, a Guinness World Record. Proposals to dam the estuary for power date back to the 19th century. In 2013 a parliamentary select committee found the case for a Severn Barrage “unproven”.
2. Ungava Bay (Leaf Lake), Canada: 9.75 m. Ungava Bay is an oval inlet of about 50,000 km² between Nunavik in northern Quebec and Baffin Island. Its south-west corner competes with Fundy for the world record. In March 2002 a range of 16.2 m was measured at the mouth of the Leaf River. The predicted extreme spring range there is 16.8 m (plus or minus 0.4 m), only 20 cm short of the figure for Burntcoat Head. One Inuktitut name for the Leaf River is Itinniq, “where there are spring tides”. NOAA also lists Leaf Bay (8.53 m), Hopes Advance Bay (8.23 m) and the Koksoak River entrance (8.69 m). It files the Koksoak under Hudson Bay, but the river actually flows past Kuujjuaq into Ungava Bay. The bay’s remoteness and long ice season have so far kept tidal power there to the study stage.
Number 1: Burntcoat Head and the Minas Basin
1. Bay of Fundy (Burntcoat Head), Canada: 11.70 m. Fundy wins on every measure: the highest mean range, the highest predicted extreme (17.0 m) and the most stations near the top of the list. The reason is resonance. The bay, an arm of the Gulf of Maine between New Brunswick and Nova Scotia, is shaped and sized so that water sloshing in and out of it takes about as long as the tide itself. Each lunar push therefore arrives in time with the last. In one half-day cycle about 100 billion tonnes of water flows in and out, roughly twice the combined flow of all the world’s rivers over the same period. High and low water are about 6 hours and 13 minutes apart.
The record lies at the head of the bay. Burntcoat Head, on the south shore of the Minas Basin, sees spring ranges of over 16 m. At low tide the Minas Basin uncovers mudflats up to 4 km wide, and the water is a nearly opaque reddish brown from sediment eroded out of Carboniferous and Triassic rock. On the New Brunswick side, the Hopewell Rocks, sea stacks 12–21 m tall, stand in water at high tide and can be walked around at low tide. The Bay of Fundy guide covers the bay’s coast and parks in more detail.
The tide reaches well inland. Most rivers that drain into Fundy have a tidal bore. A causeway built in 1968 almost wiped out the Petitcodiac bore, once up to 2 m high. After the causeway gates were opened in 2010 the bore returned, and in 2013 surfers rode it for a record 29 km. Weather can add even more water. In October 1869 the Saxby Gale, a tropical cyclone, struck on a perigean spring tide. The resulting 2 m storm surge drove the water to 21.6 m, the highest level ever recorded in the bay. Nova Scotia has also tried to use the tide for power. The 20 MW Annapolis Royal Generating Station, built into a causeway on the Annapolis River, was the only tidal power plant in North America until it shut down in 2019.
Mean range puts Fundy well clear; extreme range makes it a near tie with Ungava Bay. Fundy, Turnagain Arm and the Severn are also where you can see the effect most directly, as tidal bores, and the different patterns behind them are explained in the types of tides.